Abstract: A two-wire constant current powered transducer (10) for detecting, integrating and transmitting an acceleration signal (50) received from a piezoelectric crystal (12). The crystal is operatively coupled to rotating machinery (M) such that rotating anomalies correlative of wear or potential failure can be detected early enough for preventative maintenance. The transducer (10) includes two stages (30, 40). The first stage (30) is an integrator which integrates the acceleration to velocity. The second stage (40) is a gain stage. The gain stage operates with a PNP transistor emitter follower to control the output DC bias level and route the integrated acceleration signal back to the control system.

Abstract: A self-contained, portable, hands free, one man ultrasonic test view is disclosed. The system can include a variety of features including a semiautomatic scanner for positioning a probe at various locations within a selected region of a specimen that is powered only in one axis with the second axis being manually advanceable by the user. A second feature is a display that is mountable in front of one eye so that the user of the system can simultaneously view the displayed ultrasonic response signal with one eye while viewing the specimen with the other eye to mentally superimpose the one on the other. Another feature is the inclusion in the processor of a voice recognition device to detect and translate voice commands to select and control the operations of the processor together with a microphone for the user to deliver voice commands to the system.

Abstract: Methods and apparatus for precisely applying finely spaced grid lines to an existing shaft on site include, in a first embodiment, attachment of a master grid line carrier to the shaft. In preferred embodiments, the carrier is helically wrapped about the shaft or mated at a diagonal seam across the carrier. Photosensitive material is then applied to the shaft at one or more axial locations. The shaft is rotated and passage of the grid lines on the master is sensed. A light source synchronized to the detection of the master grid lines exposes the photosensitive material as the shaft is rotated to create identical sets of finely spaced grid lines at multiple axial locations on the shaft. The invention also includes a synchronous laser Dopper velocimeter (SLDV) which accurately senses the passage of the lines on the shaft. An extremely accurate torsional interferometer can be constructed using the SLDVs.

Abstract: A device and a method for locating and counting insects in agricultural commodities has been developed. Acoustic sensors pick up sounds emanating from adult and or larval insects. The electrical outputs of the sensors are amplified and analyzed to determine (1) the first sensor to detect the sound, (2) the second sensor to detect the sound and (3) the time difference between the first and second detection. These determinations are used to calculate the locations and numbers of insects in the agricultural commodity samples.

Abstract: An improved method and apparatus for detecting and identifying one or more resonantly vibrating blades of a turbine through the use of acoustic sensors imbedded in the stationary casing of the turbine is disclosed. The acoustic sensor signals are processed to separate the characteristic Doppler waveform from the accompanying random noise and periodic noise. Improved signal processing techniques which involve the evaluation of both an information-bearing resonant signal and its Hilbert transform via direct synthesis are disclosed.

Abstract: An acoustic temperature and/or film thickness monitoring system for semiconductor wafers in which the velocity of acoustic waves in the wafer is employed to measure temperature and/or thickness.

Abstract: A method for measuring properties of a cold rolled thin steel sheet, comprising the determination, by using a resonant electromagnetic ultrasonic wave sensor for a standing wave, of the ratio of a thickness resonant frequency of a transverse ultrasonic wave propagating within a cold rolled thin steel sheet in the direction of thickness while polarized in a direction parallel to the direction of rolling to a thickness resonant frequency of a longitudinal ultrasonic wave propagating within the cold rolled thin steel sheet in the direction of thickness, and the ratio of a resonant frequency of a transverse ultrasonic wave propagating within the cold rolled thin steel sheet in the direction of thickness while polarized in a direction normal to the direction of rolling to a thickness resonant frequency of a longitudinal ultrasonic wave propagating in the direction of thickness, and approximately determining the Young's modulus and the Lankford value according to a computing formula using the resultant two measured

Abstract: In the whole-product ultrasonic inspection system proposed, a test head mount, having an axis of rotation, is mounted on a height-adjustable test bench. A test-piece, manipulator having an axis of rotation, is also mounted on the test bench. The test head mount axis and the test-piece manipulator axis are parallel to each other. A guideway is coupled between the test bench and the test head mount or the test-piece manipulator. The guideway runs in a direction that is orthogonal to the test head mount axis and the test-piece manipulator axis. The guideway is arranged such that the test-piece manipulator can move relative to the test head mount between a test position in which the test head mount axis and the test-piece manipulator axis coincide and a service position in which an object to be tested can be received by the test head mount.

Abstract: A method and an apparatus are provided for measuring the wall thickness of a pipeline through which a fluid flows, the pipeline having an interior and exterior surface. The apparatus has a pig body supported by elastomeric cups to thereby cause the pig body to move by fluid flow through the pipeline. The pig body supports a plurality of multi-element transducers. Each transducer is made up of a large number of independent elongated rod-like crystal elements separated by a polymer, each having side walls, a front face and a bottom face. The rod-like elements are arranged so that the side walls are adjacent but mechanically isolated from each other, such as by an epoxy, with the front faces and bottom faces providing transducer front and bottom surfaces. A front metallic film and a bottom metallic film are applied to the front and the bottom surfaces. Each transducer is configured to have an impedance that closely matches the impedance of the pipeline fluid.

Abstract: An ultrasonic sensor having a polarization maintaining fibre including two orthogonal linear principal axes and a straight sensing portion. A laser source directs a beam through a quarter wave plate to provide a circularly polarized beam to an input end of the fibre. The beam emerging from an output end of the fibre is directed to a linear polarizer and the intensity of the beam is detected by a photodetector. A signal processor thereafter generates suitable driving signals for a display unit indicative of mode coupling induced in the fibre by incident ultrasonic waves.

Abstract: An improved method for repair of incore-instrumentation-housing and related defects in a nuclear reactor system involves three stages, each with ultrasonically assisted inspections. In the first stage, a defective incore housing is removed and the exposed area and aperture at the former location of the incore housing is ultrasonically inspected using an ultrasonic probe with a tiltable disk-shaped head that self-conforms to the local contour of the reactor vessel bottom. In the second stage, a weld buildup is formed. The reactor is then sealed and the weld buildup is machined to define an aperture therethrough. The weld buildup is then ultrasonically inspected with a second probe with a centering member that is stationary as the probe body is moved vertically relative to it. In the third stage, a J-prep is formed. A new incore housing is inserted through the weld buildup aperture. The new incore housing is welded at the J-prep. The J-weld is ultrasonically inspected using a third ultrasonic probe.

Abstract: A method of detecting an underground optical transmission line effectively and efficiently regardless if the optical transmission line is of a non-metallic type or not. The method comprises steps of emitting acoustic vibration from vibration generating means toward an underground area where the optical transmission line 1 is laid while moving the vibration generating means on a road roller 5 on the ground and measuring changes in the intensity of an optical signal being transmitted through the optical transmission line 1 subjected to the vibration and the displacement of the vibration generating means to determine the location of the underground optical transmission line 1 from the distribution of the intensity of the transmitted optical signal.

Abstract: A method and apparatus for the nondestructive evaluation of ferromagnetic and non-ferromagnetic materials, particularly wire ropes, cables, and strands, and pipes utilizing the magnetostrictive effect for measuring minute variations in magnetic fields and characterizing these minute variations as indicative of the acoustic/ultrasonic behavior of fractures, cracks, and other anomalies within a substance under evaluation. The apparatus and method contemplate both an active testing application, wherein a transmitting sensor generates an acoustic/ultrasonic pulse within a material through the magnetostrictive effect and a second receiving sensor detects reflected acoustic/ultrasonic waves within the material, again by the inverse magnetostrictive effect. The advantages of utilizing magnetostrictive sensors as opposed to well known piezoelectric sensors lies in the ability to generate and detect acoustic/ultrasonic waves without a direct physical or acoustical contact to the material.

Abstract: A method and apparatus for the nondestructive evaluation of ferromagnetic and non-ferromagnetic materials, particularly wire ropes, cables, and strands, and pipes utilizing the magnetostrictive effect for measuring minute variations in magnetic fields and characterizing these minute variations as indicative of the acoustic/ultrasonic behavior of fractures, cracks, and other anomalies within a substance under evaluation. The apparatus and method contemplate both an active testing application, wherein a transmitting sensor generates an acoustic/ultrasonic pulse within a material through the magnetostrictive effect and a second receiving sensor detects reflected acoustic/ultrasonic waves within the material, again by the inverse magnetostrictive effect. The advantages of utilizing magnetostrictive sensors as opposed to well known piezoelectric sensors lies in the ability to generate and detect acoustic/ultrasonic waves without a direct physical or acoustical contact to the material.

Abstract: A method of detecting a counterflow in a pump comprises providing with detecting means for detecting variations in the discharge pressure of the pump and signal analyzing means for analyzing oscillation components contained in an output signal from the pressure detecting means, and detecting the pump's operating point to have entered a counterflow characteristic operation region when a waveform of the detection signal generated in association with the variations in the discharge pressure of the pump exhibits a predetermined spectrum distribution. Further, when it is detected that the operating point enters a counterflow characteristic operation region, the escape from that region is performed by temporally throttling the guide vane and temporally increasing the rotating speed.

Abstract: The ultrasonic transducer (5) is moved along the axial direction of elements of elongate shape (1), and is electrically excited for the emission of ultrasonic waves. Electrical measurement currents originating from the transducer (5) are collected and analyzed. The transducer (5) comprises a support having a concave active surface having curved generatrices and a plurality of piezoelectric elements fixed to the active surface of the support in adjacent dispositions.

Abstract: A position sensor for measuring the distance from a first position to a second position. The sensor may include an elastic wave generator, an acoustical path over which the elastic wave passes, and a transducer to which the wave passes. A measurement loop includes the acoustical path, and has electrical and optical elements. The electrical elements may compare the phases of the transducer signals from which the change in position between the first and second positions are determined. Alternatively, the measurement loop may comprise a feedback loop to produce oscillations and an output frequency. A frequency counter is included in the feedback loop to measure frequency.

Abstract: A rotor of on ultrasonic testing device for rotation-symmetrical test-pieces has drillings arranged in pairs for test head supports and test head supports arranged in these drillings. These supports are longitudinally adjustable along the axis of the drilling. The supports are sealed in the drilling and carry at least one test head. The drillings arranged in pairs are arranged in staggered array along the axis of rotation of the rotor or around the periphery of the rotor. Each pair has a rotary drive which as a shared activating system and facilitates synchronous rotation in an opposite direction of the two test head supports of the pair around the axis of the drilling.

Abstract: In a method for the early detection and location of a change in a component of a turbine, in particular in a turbine blade, in the event of a deviation from a standard value in at least one measured value determined during operation of the turbine, an acoustic spectrum generated by the component is measured in the interior of the turbine and compared with a reference spectrum. In order to increase the intensity of signals in the acoustic spectrum, the components of the turbine, preferably runner blades, are excited from outside to acoustic emission (resonance test). An apparatus has a number of sensors for recording operating parameters of the turbine. The sensors are connected to a device for measured value conditioning. In order to detect and locate changes, an acoustic measurement probe which can be inserted from the outside into the interior of the turbine, is connected to the device.

Abstract: An improved accelerometer comprising a transducer responsive to vibration in machinery which produces an electrical signal related to the magnitude and frequency of the vibration; a decoding circuit responsive to the transducer signal which produces a first fault signal, and isolating circuitry responsive to the first fault signal to produce a second fault signal in which ground shift effects are nullified.